It begins on Wednesday at 20.00 UK time (19.00 GMT) at Celtic Park.

While Lazio’s aircraft from Rome did arrive on schedule, the post-Brexit security clearance took much longer than anticipated. As a result, the press conference and pitch inspection had to be postponed by one hour.

That added to Sarri’s negative attitude, which was already apparent after his remarks on the transfer plan over the weekend generated conflict with President Claudio Lotito.

“The problem is when the media report only two out of eight words that you say and not all of them. To minimize misunderstanding going forward, I may just respond with yes and no,” the coach said.

Although Scottish football has a reputation for being extremely physical, Sarri does not anticipate the Hoops to play that way.

It is the least physically demanding game of the lot. Although they don’t play with much physical force, they are a very dynamic squad.

Celtic appear to be a very dangerous team in several ways. They shocked me with their technical ability, and they had earned more against Feyenoord before the red cards.

When Brendan Rodgers was in charge of Leicester City, Sarri had previously encountered him.

We are in the Champions League, which is a very different competition from Serie A, therefore we have nothing to make up for. All we need to do is maintain our level of competition. There is no need to look for any further inspiration.

The main challenge Sarri has faced during his tenure has been a lack of consistency in approach and performance, sometimes even within the same game.